In a radio communication system of Long Term Evolution (LTE) and the like that are standardized in 3rd Generation Partnership Project (3GPP), when a mobile station transmits uplink data, the mobile station is configured to transmit a scheduling request for requesting the assignment of a radio resource in an uplink radio link to a base station (for example, Non Patent Literature 1).
On the basis of the received scheduling request, a base station transmits scheduling permission including assignment information of the radio resource to the mobile station. On the basis of the received scheduling permission, the mobile station transmits uplink data by using an assigned radio resource, specifically, a schedule-type access channel (a shared data channel).